1. Field of the Invention
This invention is in the field of fuel injection systems for internal combustion engines, wherein the fuel is injected into the engine intake manifold.
2. Description of the Prior Art
The prior art of four stroke cycle internal combustion engines, using intake manifold fuel injectors, is described in U.S. Pat. No. 5,456,232, Col. 1, line 57, through Col. 4, line 15, and this material is incorporated herein by reference thereto. Some types of intake manifold fuel injectors proportion the instantaneous fuel injection rate to the instantaneous air flow rate, during each engine intake process, so that the resulting engine intake air-fuel mixture is essentially of a constant fuel to air ratio throughout the air mass quantity going into each engine cylinder during each intake process. An example of such a gasoline engine fuel injection system is described in U.S. Pat. No. 5,456,232, Col. 4, line 35, through Col. 19, line 9, and this material is incorporated herein by reference thereto. These manifold fuel injectors of U.S. Pat. No. 5,456,232, are described therein as useable on four stroke cycle internal combustion engines, but are also useable on two stroke cycle internal combustion engines, by setting the timing of fuel injection to coincide with the timing of air intake flow, during each engine air intake process.
Manifold fuel injector systems need compensator schemes, when engine speed and load vary over a wide range. Examples of prior art compensators, for manifold fuel injectors are described in the following references:
A. U.S. Pat. No. 5,456,232; Col. 13, line 40, through Col. 18, line 51: PA1 B. U.S. Pat. No. 5,483,937 PA1 C. U.S. Pat. No. 5,613,475
These compensator schemes are relatively complex mechanically. It would be beneficial to have available a compensator scheme capable of adequately compensating a manifold fuel injector over a wide range of engine speed and load, of relative mechanical simplicity.